Tapping Diversity From the Wild: From Sampling to Implementation

Abstract

The diversity observed among crop wild relatives (CWRs) and their ability to flourish in unfavorable and harsh environments have drawn the attention of plant scientists and breeders for many decades. However, it is also recognized that the benefit gained from using CWRs in breeding is a potential rose between thorns of detrimental genetic variation that is linked to the trait of interest. Despite the increased interest in CWRs, little attention was given so far to the statistical, analytical, and technical considerations that should guide the sampling design, the germplasm characterization, and later its implementation in breeding. Here, we review the entire process of sampling and identifying beneficial genetic variation in CWRs and the challenge of using it in breeding. The ability to detect beneficial genetic variation in CWRs is strongly affected by the sampling design which should be adjusted to the spatial and temporal variation of the target species, the trait of interest, and the analytical approach used. Moreover, linkage disequilibrium is a key factor that constrains the resolution of searching for beneficial alleles along the genome, and later, the ability to deplete linked deleterious genetic variation as a consequence of genetic drag. We also discuss how technological advances in genomics, phenomics, biotechnology, and data science can improve the ability to identify beneficial genetic variation in CWRs and to exploit it in strive for higher-yielding and sustainable crops.

Decoupling the molecular regulation of perenniality and flowering in bulbous barley (Hordeum bulbosum)

“…Nevertheless, previous attempts to develop a perennial crop through classical breeding methods has extended over long periods due to challenging crosses between species, a sever genetic drag, and declining yield under field conditions (Kantar et al, 2016;Lundgren and Des Marais, 2020). Therefore, breeding towards perennial crops should become more targeted and incorporate biotechnological practices in the breeding process (Hübner and Kantar, 2021).…”

“…Unlike annual crops, perennials are thriftier and improve soil structure and water retention capacity, contribute to increased mitigation practices to cope with climate change, and promote biodiversity and ecosystem functions (Kantar et al, 2016;Lundgren et al, 2020). Among annual crops that are cultivated across over 70% of global croplands, many staple crops could potentially be transferred to a perennial life habit by hybridization and other genomic engineering techniques (Hübner and Kantar 2021). Generally, there are two main approaches to develop a new perennial crop: de novo domestication of a wild perennial plant, and introgression of perennial traits into an annual crop through hybridization practices (Cui et al, 2018;Kantar et al, 2018).…”

Wild sunflower goes viral: Citizen science and comparative genomics allow tracking the origin and establishment of invasive sunflower in the Levant

“…Another challenge of studying an alien species is the limited information available on its distribution in the invaded region, especially for recently introduced species that are not included in the local flora documentation. Failure to properly represent the distribution of the target species may result in biased inferences on the level of genetic variation and divergence (Hübner & Kantar, 2021).…”

“…Failure to properly represent the distribution of the target species may result in biased inferences on the level of genetic variation and divergence (Hübner & Kantar, 2021).…”

Crop Improvement: Now and Beyond

“…Crop wild relatives (CWRs) are still present in natural habitats where they are able to develop adaptive traits to face environmental constraints; for example, this could be an efficient way to cope with drought tolerance [ 3 , 4 ]. CWRs have been exploited to improve crops for decades (for a review, see [ 5 ]). For example, Oryza glaberrima was used to improve cultivated rice ( O. sativa ; [ 6 ]), Solanum pennellii for tomato ( S. lycopersicum ; [ 7 ]), wild Solanum species for potato [ 8 ], wild Gossypium species for cotton ( G. hirsutum ; [ 9 ]) and Aegilops ventricosa for bread wheat ( Triticum aestivum ; [ 10 ]).…”